The banner that erroneously heralds visiting celebrity Bramwell Wink-Porter as author of The Fuzzy Bunny typifies the mishaps at Melvinville Elementary School, the setting for Pinkwater's latest droll excursion. (The principal entreats her guest to talk about the misascribed title anyway, since all the children have read it.) Wink-Porter dutifully answers students' questions (``What is the greatest number of hot dogs you have eaten at one sitting?''), downs the eponymous hare's favorite sandwich--bologna and shredded carrots with extra mayonnaise--and agrees to a return visit so the sixth-graders can finish tying him up. While children may enjoy some of Pinkwater's humor, the farcical asides and non sequiturs here possess a generally adult sensibility. Also, the narrative seems overlong for the picture-book format, and the plot too sophisticated and specific to engage this age group. The illustrations do little to advance the action in this disappointing effort. Ages 5-8. (Apr.)